INFLUÊNCIA DA POSIÇÃO SOCIAL E DO NÚMERO DE RAIOS NA ESTIMATIVA DA ÁREA DE COPA EM ARAUCÁRIA

O objetivo do presente estudo foi avaliar a precisao e a acuracia na estimativa da area de projecao horizontal da copa de araucaria em diferentes posicoes sociais. Foram amostradas 294 arvores na floresta e classificadas, conforme a sua posicao sociologica, em dominante, codominante e dominada. Em cada arvore foram medidos o diâmetro a altura do peito, a altura total e oito raios de copa seguindo a direcao dos pontos cardeais. A area de projecao horizontal da copa foi calculada pela media dos respectivos numeros de raios avaliados na copa (metodos): oito, quatro e dois. As diferencas estatisticas entre os metodos foram verificadas por analise de variância com arranjo fatorial, considerando dois fatores, os metodos de area de copa e a posicao social ocupada pelas arvores. Os resultados indicaram que, apesar de nao haver diferenca significativa entre as medias de area de projecao da copa quando medido oito e quatro raios, a analise grafica evidenciou tendencia de superestimativa da area quando calculada com quatro e dois raios em copas irregulares, frequentemente encontradas nas arvores codominantes e dominadas. Ademais, em copas simetricas, a determinacao da area de projecao horizontal da copa com quatro raios pode ser empregada sem perda de acuracia. Abstract Influence of social position and number of radius in estimate of area in araucaria crown. The aim of this study was to evaluate precision and accuracy in estimating horizontal projection crown area of trees of Araucaria Angustifolia in different social positions. We sampled 294 trees in the forest and classified them according to their position in sociological position as dominant, codominant and dominated. In each tree it was measured the diameter at breast height, total height and eight crown radius following the cardinal points direction. The horizontal projection area of the crown was calculated by the average of the respective radius numbers evaluated in the crown (methods): eight, four and two. Statistical differences between among methods were verified by variance analysis with factorial arrangement, considering two factors, methods of crown area and the social position occupied by trees. The results indicated that although there was no significant difference between the mean area of crown projection when measured eight and four radius, the graphical analysis revealed tendency to overestimate the area  calculated with four and two radius in irregular crown, often identified in codominant and dominated trees. Furthermore, in relation to symmetrical crowns, determining the area of horizontal projection crown with four radius can be used without loss of accuracy. Keywords: Crown diameter; horizontal crown surface; social class; araucaria forest.